In tracing out the approach to Bligh's Farewell, you will be led to examine the southern face of New Guinea as far as Cape Valsche; but after verifying the position of this point, it will be prudent to quit the shores of that island, and not to meddle with any part of it over which the Dutch claim jurisdiction. When you have arrived at this distant point, the south-east monsoon will probably render it necessary to repair to Port Essington for such supplies as may by previous arrangement have been sent there for you from Sydney; or perhaps unforeseen events might render it more expedient to proceed for refreshments to some of the islands in the Arafura Sea, or it is possible to one of the Dutch settlements in Java. And in either of these two latter cases you should make a complete survey of the island to which you have proceeded, or you should select any one of the eastern passages from Bally to Floris most convenient to the object you have in view, and then lay it down with precision. Of the many well-known passages between the innumerable islands of that great Archipelago, there is not one which has ever been charted with plausible accuracy; and it cannot be too strongly impressed on your mind that hydrography is better served by one accurate chart than by ten approximate sketches. The several objects of this highly interesting expedition having thus been briefly enumerated, I have only to remind you that their Lordships do not prescribe to you the order in which they are to be executed, leaving it to your own prudence, and to your experience in those climates, so to arrange them that each part of your survey shall be complete in itself, and that each step in your progress shall be conducive to its successor. Signed: F. BEAUFORT, HYDROGRAPHER. ... SAIL FROM PLYMOUTH. The Rattlesnake left Spithead on December 3rd, and on the 11th took her final departure from Plymouth, which place we had called at to complete her fittings, swing the ship a second time to ascertain the amount of local attraction, and receive some specie for the Cape of Good Hope and the Mauritius. Being favoured by strong northerly winds, we reached Madeira on December 18th, after a quick, but most uncomfortable passage; during the greater part of which the main and lower decks were partially flooded, owing to the inefficiency of the scuppers, and the leaky state of nearly every port and scuttle in the ship. ARRIVE AT MADEIRA. December 20th.